Energy storage systems (e.g., battery energy storage systems) have become increasingly used to deliver power either as part of standalone energy storage systems or as part of power generation systems (e.g., a wind farm, solar farm, gas turbine system) with an integrated energy storage system. Energy storage systems are unique in that energy storage systems have the ability to both deliver and reserve energy for particular services. Energy storage systems can include one or more battery banks that can be coupled to the grid or other load via a suitable power converter.
Renewable energy power systems, such as wind energy power systems and solar energy power systems, often include a power converter with a regulated DC bus. For example, wind power systems, such as wind driven doubly-fed induction generator (DFIG) systems or full power conversion systems, can include a power converter with an AC-DC-AC topology. Solar power systems can include a power converter that has a DC-DC-AC topology.
An energy storage system can be coupled to the DC bus of a power converter in a renewable energy system. The energy storage system can be used, for instance, to apply power to the DC bus of the power converter during transient conditions. A switching power supply can be provided to transfer energy back and forth between the DC bus of the power converter and the energy storage device. For instance, the switching power supply can include a DC to DC converter configured to convert a first voltage on the DC bus to a second voltage at the energy storage device, and vice versa.